The present invention relates to a linear path slide with a slide which is arranged slidingly movable in a housing along a sliding guide and safe against torsion and with a hydraulic driving gear integrated into the slide for a shifting movement of the slide.
Linear path slides of the type according to the kind are known. They are used in particular as actuators in different devices for the processing and machining of metallic materials and plastic or plastic composite materials. The functions of these structural components typically include the pressing, forming, stamping, bending, beading, punching, cutting, jointing, jointing pressing as well as the carrying out of feeding functions with special requirements. Particular requirements are made to the properties of linear path slides among which, in particular, a very high energy density, a very high guiding exactitude as well as a very high stiffness against transverse loads and torsion are to be found. Furthermore, linear path slides should be constructed as compact as possible and allow, as standardized basic structural components, a flexible universal range of application. Moreover, properties such as maintenance-freedom during the whole lifetime, a robust construction for the use in polluted environment, the possibility of any fitting position, absolute tightness (for example by overhead mounting) and not least a low-cost production are desirable.
Different configurations of linear path slides are known. Because of the required high energy density, they are preferably hydraulic devices. However, basically the design as a pneumatically driven device is also possible.
From the EP 1 050 685 A2, we know a linear path slide in which a hydraulic driving gear is integrated into the slide for obtaining a compact construction and a reduced volume and thus a reduced weight.
The aim of this invention is to create a linear path slide of the type according to the kind which can realize high actuation forces by maintaining a compact construction.
According to the invention, this aim is achieved by a linear path slide with the characteristics indicated in claim 1. By the fact that a working piston of the hydraulic driving gear is configured at least with two stages, whereby each stage of the working piston forms a partial hydraulic driving gear of the hydraulic driving gear, it is advantageously reached that an increase of the actuation force of the linear path slide is obtained according to the selected multiple-stage design. The actuation forces applied by the individual partial stages are superimposed and thus result in a higher total actuating force.
Thus, due to such linear path slides, high processing forces are applied by maintaining an exact guiding and a high stiffness against transverse loads, for example for cutting tools.
In a preferred embodiment of the invention, it is provided for that the working piston comprises a guiding element guided slidingly along the housing, guiding element which coaxially encompasses a piston rod fixed with respect to the housing, whereby the guiding element constitutes two inner spaces axially spaced to the piston rod and sealed against each other. Due to such a configuration, it is advantageously reached to use the size available for constituting the partial hydraulic driving gears. In particular, there results then a parallel efficacy of the partial hydraulic driving gears so that the increase of the actuation force of the linear path slide can be obtained in a simple way.
According to a further preferred embodiment, two hydraulic working spaces sealed against each other are respectively configured in each of the inner spaces of the guiding element sealed against each other, whereby these working spaces can be optionally charged with hydraulic oil under pressure. Thus, it is advantageously reached that either the adjusting movement of the linear path slide, or the reset movement of the linear path slide can be hydraulically activated.
Further preferred embodiments of the invention result from the other characteristics indicated in the subclaims.